There are numerous instances in which it is very desirable, if not necessary, to monitor the surface temperature of a vessel. For example, monitoring the temperature of the exterior surfaces of process vessels, especially those used in exothermic processes, provides process operators with information that can be used to prevent vessel failure that could result if vessel design limits were to be exceeded.
Thus one object of the present invention is to provide a reliable sensor for monitoring the surface temperature of a metal vessel.
Another object of the invention is to provide a reliable sensor that can be replaced while the vessel is in service.